► The goal of this Thesis is to present a philosophical interpretation of the idea/event of "Polemos". Focusing on the philosophical thought of Heraclitus and Martin…
(more)

▼ The goal of this Thesis is to present a philosophical interpretation of the idea/event of "Polemos". Focusing on the philosophical thought of Heraclitus and Martin Heidegger we will approach "Polemos", not only ontically, as a military struggle, but, ontologically as well, as expressed in the struggle of the human being to find/create his abode in the world. Our effort will center on the definition of the human being as "Deinotaton"- a definition made by Sophocles in the choral ode of Antigone- and on the nature of modern warfare. Finally, we will try to show why and how human being ¿s conscience is getting fragmented in the war¿s perception by modern society and how this fragmentation may be countered through the eventuation of "logos" in the thought/ life of the human being.
Advisors/Committee Members: Aguirre Santos, Javier (advisor).

► Over the past decade, new concepts have emerged in the electricity field, including the Smart Grids, the Distributed Generation and the Microgrids (MGs). In this…
(more)

▼ Over the past decade, new concepts have emerged in the electricity field, including the Smart Grids, the Distributed Generation and the Microgrids (MGs). In this thesis, we will be mainly focusing on the study of the MGs. An MG is a small-scale power system, consisting of local power generation.
Advisors/Committee Members: Camblong Ruiz, Aritza (advisor).

▼ During this thesis, we fabricated infrared (IR) antennas and transmission lines (TLs), and characterizedthem by transmission-mode scattering-type scanning near-field optical microscopy (transmission-mode s-SNOM). By means of dipolar antennas we coupled mid-IR light into two-wire TLs and we investigatedpropagation properties such as local field enhancement, field confinement, mode (effective) wavelength,propagation length. In addition, we studied for the first time more complicated antenna structure such asArchimedean spiral antennas, which is a well-know travelling wave broadband antenna for radio-wavetechnology. To that end, we modified the transmission-mode s-SNOM setup available at nanoGUNE tobe able to illuminate the samples with circularly polarized light. In order to support the experimentalobtained near-field distributions, we have performed FDTD and FDFD simulations, which are inexcellent agreement with the experimental data.
Advisors/Committee Members: Hillenbrand, Rainer (advisor).

► [EN]This Thesis covers a broad period of research activities with a commonthread: learning processes and its application to image processing. The twomain categories of learning…
(more)

▼ [EN]This Thesis covers a broad period of research activities with a commonthread: learning processes and its application to image processing. The twomain categories of learning algorithms, supervised and unsupervised, have beentouched across these years. The main body of initial works was devoted tounsupervised learning neural architectures, specially the Self Organizing Map.Our aim was to study its convergence properties from empirical and analyticalviewpoints.From the digital image processing point of view, we have focused on twobasic problems: Color Quantization and filter design. Both problems have beenaddressed from the context of Vector Quantization performed by CompetitiveNeural Networks. Processing of non-stationary data is an interesting paradigmthat has not been explored with Competitive Neural Networks. We have statesthe problem of Non-stationary Clustering and related Adaptive Vector Quantizationin the context of image sequence processing, where we naturally havea Frame Based Adaptive Vector Quantization. This approach deals with theproblem as a sequence of stationary almost-independent Clustering problems.We have also developed some new computational algorithms for Vector Quantizationdesign.The works on supervised learning have been sparsely distributed in time anddirection. First we worked on the use of Self Organizing Map for the independentmodeling of skin and no-skin color distributions for color based face localization. Second, we have collaborated in the realization of a supervised learning systemfor tissue segmentation in Magnetic Resonance Imaging data. Third, we haveworked on the development, implementation and experimentation with HighOrder Boltzmann Machines, which are a very different learning architecture.Finally, we have been working on the application of Sparse Bayesian Learningto a new kind of classification systems based on Dendritic Computing. This lastresearch line is an open research track at the time of writing this Thesis.
Advisors/Committee Members: Graña Romay, Manuel María (advisor).

► [EN]The practical context of this thesis work is natural interaction in Interactive Multimedia Tabletops using visually recognized hand gestures. An interaction language has been de…
(more)

▼ [EN]The practical context of this thesis work is natural interaction in Interactive
Multimedia Tabletops using visually recognized hand gestures. An
interaction language has been de ned for the speci c characteristics of
this kind of systems and applications. Hand gestures are captured using
an optical video camera, then the image is processed to obtain the hand
shape skeleton. Gesture recognition is performed using pattern matching
techniques speci cally designed to work on the information provided
by skeletal representations of the shapes in the image. This thesis work
introduces a theoretical and computational contribution to the skeleton
computation procedure which achieves better stability than other algorithms
in the literature. This contribution starts from Voronoi skeleton
computation method and based in results which permit an e cient and
robust pruning, obtains stable skeletons in realtime (60fps), which make
possible the application of this technique in the context of Interactive
Multimedia Tabletops
Advisors/Committee Members: Graña Romay, Manuel María (advisor).

► Consensus is one of the fundamental problems in fault tolerant distributed systems. In addition to the importance of the problem itself, consensus can be a…
(more)

▼ Consensus is one of the fundamental problems in fault tolerant distributed systems. In addition to the importance of the problem itself, consensus can be a way to solve many other problems in distributed systems, so it is considered a key topic in the Distributed Computing area. Although many solutions have been proposed to solve consensus in synchronous systems, [Fischer, Lynch, and Paterson, 1985] presented an impossibility result, namely Fischer-Lynch-Paterson or FLP, that states that it is impossible to reach consensus in asynchronous systems where even one process may crash. In order to circumvent FLP, [Chandra and Toueg, 1996] proposed the unreliable failure detector abstraction, which has been widely studied in several systems, especially those where processes can only fail by crashing. Failure detectors offer a modular approach that allows other applications such as consensus to use them as a building block. Additionally, the failure detector abstraction allows to encapsulate the synchrony assumptions of the system, so that applications which make use of failure detectors can be designed as if they run in pure asynchronous systems. In this work we show that failure detectors can also be applied to the general omission failure model, in which processes may fail by crashing and by omitting messages either when sending or receiving. As a practical example, we propose a solution to a security area problem called Secure Multiparty Computation by using failure detectors for general omission. In the context of failure detectors in the crash failure model we also study communication efficiency, a performance measure achieved when there are only n links that carry messages forever, being n the number of processes. We improve this measure by defining communication optimality, in which only c links are needed, being c the number of correct processes. In this regard, we propose some communication-optimal implementations of the eventually perfect failure detector class <>P. Finally, we propose a communication-efficient implementation of a failure detector for the general omission failure model. In this case, we define communication efficiency as a linear number of links carrying messages forever.
Advisors/Committee Members: Soraluce Arriola, Iratxe (advisor), Lafuente Rojo, Julián Alberto (advisor).

► This PhD Thesis deals with the segmentation of hyperspectral images from the point of view of Lattice Computing. We have introduced the application of Associative…
(more)

▼ This PhD Thesis deals with the segmentation of hyperspectral images from the point of view of Lattice Computing. We have introduced the application of Associative Morphological Memories as a tool to detect strong lattice independence, which has been proven equivalent to affine independence. Therefore, sets of strong lattice independent vectors found using our algorithms correspond to the vertices of convex sets that cover most of the data. Unmixing the data relative to these endmembers provides a collection of abundance images which can be assumed either as unsupervised segmentations of the images or as features extracted from the hyperspectral image pixels. Besides, we have applied this feature extraction to propose a content based image retrieval approach based on the image spectral characterization provided by the endmembers. Finally, we extended our ideas to the proposal of Morphological Cellular Automata whose dynamics are guided by the morphological/lattice independence properties of the image pixels. Our works have also explored the applicability of Evolution Strategies to the endmember induction from the hyperspectral image data.
Advisors/Committee Members: Graña Romay, Manuel María (advisor).

► [EN]Computer simulation has become a powerful technique for assisting scientists in developing novel insights into the basic phenomena underlying a wide variety of complex physical…
(more)

▼ [EN]Computer simulation has become a powerful technique for assisting scientists in developing novel insights into the basic phenomena underlying a wide variety of complex physical systems. The work reported in this thesis is concerned with the use of massively parallel computers to simulate the fundamental features at the electronic structure level that control the initial stages of harvesting and transfer of solar energy in green plants which initiate the photosynthetic process.
Currently available supercomputer facilities offer the possibility of using hundred of thousands of computing cores. However, obtaining a linear speed-up from HPC systems is far from trivial. Thus, great efforts must be devoted to understand the nature of the scientific code, the methods of parallel execution, data communication
requirements in multi-process calculations, the efficient use of available memory, etc. This thesis deals with all of these themes, with a clear objective in mind: the electronic structure simulation of complete macro-molecular complexes, namely the Light Harvesting Complex II, with the aim of understanding its physical behaviour.
In order to simulate this complex, we have used (with the assistance of the PRACE consortium) some of the most powerful supercomputers in Europe to runOctopus, a scientific software package for Density Functional Theory and Time-Dependent Density Functional Theory calculations. Results obtained with Octopus have been analysed in depth in order to identify the main obstacles to optimal scaling using thousands of cores. Many problems have emerged, mainly the poor performance of the Poisson solver, high memory requirements, the transfer of high quantities of complex data structures among processes, and so on. Finally, all of these problems have been overcome, and the new version reaches a very high performance in massively parallel systems. Tests run efficiently up to 128K processors and thus we have been able to complete the largest TDDFT calculations performed to date. At the conclusion of this work it has been possible to study the Light Harvesting Complex II as originally envisioned.
Advisors/Committee Members: Muguerza Rivero, Javier Francisco (advisor), Rubio Secades, Angel (advisor).

► The thesis work is focused on the characterization of the neurophysiology of dorsal raphe neurons and the behavioral response in depression-related tests in mice lacking…
(more)

▼ The thesis work is focused on the characterization of the neurophysiology of dorsal raphe neurons and the behavioral response in depression-related tests in mice lacking GIRK2 subunits and study of the effect of ketamine in the glutamatergic transmission of the dorsal raphe. The findings show the specific role of GIRK2 subunit- containing GIRK channels in the promotion of a depression-resistant phenotype, as well as their control of the tonic neuronal activity and mediation of the 5-HT1A receptor inhibitory responses. Moreover, the results show the involvement of GIRK2 subunit-containing GIRK channels in the behavioral response to the selective serotonin reuptake inhibitor citalopram. This could lead to development of new strategies targeting the 5- HT1A-GIRK2 pathway with great therapeutic interest for the study of pathologies related to an altered 5-HT transmission as in major depression. In addition, it is also investigated the possible role for glutamatergic transmission to alter electrophysiological properties of dorsal raphe neurons. Previous evidence indicates that glutamatergic antagonists as ketamine are emerging as new therapies for treatment of depressive symptoms. In conclusion this thesis shows that the pharmacological blockade or deletion of the GIRK2 subunit could limit the occurrence of depression-related behaviors, and specifically addressing GIRK2 subunits in the DR could give rise to new antidepressant therapies. Additionally, the dorsal raphe composes a target for new therapeutic strategies aimed at the interactions of the serotonin-glutamate transmission.
Advisors/Committee Members: Ugedo Urruela, Luisa (advisor), Torrecilla Sesma, María (advisor).

Llamosas Muñozguren, Nerea. “New insights into the treatment of depression: role of girk channels and the glutamatergic antagonist ketamine in the neurophysiology of the dorsal raphe nucleus
.” 2015. Web. 19 Mar 2018.